The current invention relates to hydraulic systems for performing work. Hydraulic systems are used in many different applications such as automobiles, trucks, construction equipment, elevators, submarines, and many others. Hydraulic systems may be used to improve such areas as fuel efficiency and power output of mechanical systems which require energy to perform various forms of work, such as lifting payloads, propelling vehicles, or raising elevators. In some applications, it may be desirous to have energy storage in the hydraulic system to provide extra energy when needed.
In hydraulic circuits, hydraulic accumulators have been used to store excess hydraulic fluid. These hydraulic accumulators may comprise an elastic bladder within a rigid chamber. A compressible medium such as a gas may be disposed within the chamber outside of the elastic bladder, while the hydraulic fluid may be disposed within the elastic bladder. When the volume of hydraulic fluid in the bladder increases, the bladder compresses against the compressible medium thereby generating a potential energy within the rigid chamber which is stored outside of the elastic bladder.
U.S. Pat. No. 6,807,988 to Powell et al., which is herein incorporated by reference for all that it contains discloses a flexible hose adapted construction for conveying fluids under pressure. The construction includes a core tube having a circumferential inner core tube surface. A first reinforcement layer surrounds the outer core tube surface, and is formed of one or more filaments of a first fiber. A second fiber reinforcement layer surrounds the first reinforcement layer, and is formed of one or more filaments of a second fiber. The first and second reinforcement layers are bonded together by means of a bonding agent such as an adhesive, resin, plasticizer, tackifier, or solvent, the application of which is controlled to wet on a portion of the filaments of the reinforcement layers.
U.S. Pat. No. 5,042,532 to Gilleland, which is herein incorporated by reference for all that it contains discloses a pipeline repair and leak sealing system effected by unrolling a tube, using an inflatable mandrel disposed inside the tube, to radially expand a stretchable and circumferentially continuous gasket or sealant sleeve into flush contact with the pipeline interior. Before actuation, the tube is constrained in a rolled-up condition by a shrink-wrap sleeve of plastic film that may be sealed at its ends to an interior film sleeve in order to protect the tube against moisture. When fully expanded, the tube includes longitudinally-extending edges that overlap and are secured together by adhesive issued from a rupturable package disposed proximate one of the edges so as to be caused to burst as the edges approach overlapped positions. An outer sleeve of scrim material surrounds the tacky or gum-like gasket sleeve to facilitate handling and movement of the assembly in the pipeline. When the tube and gasket sleeve are expanded, the scrim material becomes embedded in the tacky gasket sleeve material which thereby protrudes through the scrim interstices to assure proper sealing and compression of the gasket sleeve against the pipeline interior wall.
U.S. Pat. No. 4,733,603 to Kukolj, which is herein incorporated by reference for all that it contains discloses an actuator that has a first connection point and a second connection point at opposite ends and is contractible along an axis extending between the connections points. The actuator has at least one hollow enclosure with an opening for admitting a pressurized fluid. A simultaneously radially expandable, axially contractible constraining means cooperates with the enclosure. The constraining means converts radial expansion of the actuator into axial contraction when pressurized fluid is admitted into the enclosure. In a preferred form, the constraining means comprises a network of non-stretchable, flexible tension links.